Automatic control for electric signs



July 3, 1934. E. HARRls ET AL 1,964,943

AUTOMATIC CONTROL FOR ELECTRIC SIGNS Filed Dec. 24, 1 31 2 Sheets-Sheet 1 Irv/ente s. .9arnefE //arr/$ 4.

July 3, 1934. G. E. HARRIS ET" AL 6 AUTOMATIC CONTROL FOR ELECTRIC SIGNS Filed Dec. 24, 1931 2 Sheets-Sheet 2 Inventors. same /'.E. Harris WlY/lalrrl SfuM/nsu Patented July 3, 1934 AUTOMATIC CONTROL FOR ELECTRIC SIGNS Garnet E. Harris and William Stubbins, Toronto, Ontario, Canada Application December 24, 1931, Serial No. 583,128

2 Claims.

The principal objects of the invention are to materially simplify the control mechanism for effecting the automatic changing of lighting equipment, "particularly in electric signs in which illuminated letters are used to spell out messages and to eliminate many of the difiiculties incident to the operating of electric switches for controlling the lighting current.

A still further object is to provide a mechanism which will be extremely compact and can be furnished and operated at remarkably low cost thus enabling such equipment to be utilized in comparatively inexpensive installations.

The principal features of the invention consist in the novel arrangement and use of pneumatically operated electric contact devices whereby such contacts may be controlled by changeable perforated strips, the contacts being arranged in an air chest separate from the chest communicating with the passages directly controlled by the perforated strip.

A further important feature consists in the novel arrangement of means for controlling variable pressures whereby the load carried by the power-operated pressure-regulating device will be maintained substantially uniform.

In the accompanying drawings, Figure 1 is a sectional elevational view of an equipment embodying the present invention.

A Figure 2 is an enlarged sectional view of the pneumatic control apparatus.

Figure 3 is a partial front elevational view of the tracker bar and perforated control strip. Figure 4 is an enlarged sectional perspective detail of a portion of the electric contact structure.

Figure 5 is a sectional elevational view of a modified arrangement of the pneumatic control mechanism.

In the operation of changeable electric signs it has been the common practice to operate the switch elements mechanically and such mechanism is very cumbersome, is difiicult and expensive to alter and requires constant manual attendance while in operation.

In the present device a casing 1 is provided in the form of an elongated rectangular box having a plurality of fixed electric contacts 2, here shown in the form of threaded pins secured in the top 3 and extending downwardly into the air chest 4.

The contacts are preferably arranged in one or more parallel rows and the wires 5 secured to said contacts outside of the casing 1 are con-- nected with the electric lamps 6 arranged in the sign or other display which is here merely diagrammatically shown. The lamps may be grounded to a common contact or return wires from the lamps may be connected to a common return wire '7, shown in Figure 4 as connected to a rod 8 extending longitudinally within the Go air chest 4. being supported above the bottom 9 of the casing l on brackets 10. A suitable feed from a source of electric supply is connected to the wire '7 but is not shown.

Recesses 11, preferably circular in form are formed in the upper side of the bottom 9 of the air chest 4 and these are covered by a thin flexible diaphragm 12, preferably of leather.

Rounded discs 13 of felt or other light material are secured on the upper surface of the diaphragm, each being arranged centrally over the recesses 11 which are arranged centrally below the downwardly projecting contacts 2.

Metal plates 14 are pivotally mounted on the longitudinally arranged rod 8 and are conse- 7,5 quently electrically connected with the wire 7 connected with the lamps. The pivotal plates 14 normally rest upon the discs 13 and when the diaphragms are raised, by a difference in air pressure between the air chest 4 and any go of the recesses 11, the corresponding plates are lifted to engage the adjacent ends of the contacts 2 thereby closing the electric circuit.

Each of the recesses 11 is connected by a separate tube 15 to a tracker bar" 16 which is of the type used in player pianos.

A strip of paper X or other suitable material is mounted on the rollers 17 and 18 arranged above and below the tracker bar 16 and this strip is perforated with openings 19 which are arranged to open the ports 20 in the tracker bar in the desired position to operate the contact members 14.

The air chest 4 is connected by a conduit 21 to a conduit 22 leading to a suitable motor-operated vacuum device 23 and a substantially constant pressure lower than atmosphere is maintained in the chest 4.

Bleed holes 24 and 25 connect the recesses 11 below the diaphragms with a chest 26 formed in the casing 1 and this chest is connected to the conduit 22 by a conduit 2'7. A valve 28 may be arranged in the conduit 27 and is operated to be turned therein by a crank 29 extending therefrom. The crank 29 is in turn operated by an arm 30 extending from the movable element 31 of a pneumatic or bellows 32 mounted on a casing 33.

The casing 33 has a vacuum chest 34 therein connected to the conduit 22. A valve 35 is ar-,

ranged between the chest 34 and a chamber 36 arranged thereabove and normally remains closed. A duct 37 connects the pneumatic 32 with the chamber 38 and when the valve is lifted the pneumatic is operated to turn the valve 28 to close the conduit 27.

A valve 38 is arranged above the valve 35 and is operated to close the port 39, which opens to atmosphere, when the valve 35 is lifted and opens,

allowing atmospheric pressure to enter the pneumatic when the valve 35 closes.

The valve 35 is mounted on a diaphragm 40 which covers the top of a recess 41 at the bottom of the chest 34. A bleed hole 42 connects the recess 41 with the chest 34. A conduit 43 leads from the recess ll to a port 44 in the tracker bar.

The strip X is provided with holes 45 which register with the port 44 and open said port to atmosphere when any of the other ports of the tracker bar are open.

It may be found desirable to operate the contact operating diaphragms by a pressure above atmosphere instead of maintaining a vacuum in the various chests described and in Figure 5 a modification is shown in which the tracker bar 46 is arranged within an air-tight casing 47 and an air pressure is maintained in said casing by means of a suitable pressure pump unit 48.

It has not been deemed necessary to show any 39 means for operating the perforated strip as such mechanism will be that commonly used in player piano construction.

t will be understood from this description that a practically endless selection of operations of the lights may be obtained and that changes may be made in the operation of the lights almost instantaneously and the simplicity and compactness of the device will be readily apparent.

What we claim as our invention is:-

1. A pneumatic switch control comprising in combination a vacuum chamber having upper and lower walls spaced apart, said lower wall having a plurality of bottomed recesses therein, flexible diaphragms applied to the upper surface of said bottom wall and overlying said recesses to form extensible walls therefor, moveable contacts resting on the flexible walls of said recesses, said upper wall of the vacuum chamber having a plurality of holes therethrough in substantial register with the flexible walls of the recesses in the lower wall, contact terminals sealed in said upper wall openings and having contact portions disposed within the vacuum chamber above said flexible walls to be engaged by said moveable contacts on the extension of said flexible walls, said contact terminals having their outer ends extending above the upper wall of said vacuum chamber, and binding nuts threaded on the said upper ends of said contact terminals, said recesses being adapted to selectively receive atmospheric pressure to extend the flexible walls there- 2. A pneumatic control comprising in combination a vacuum chest having upper and lower walls spaced apart, spaced rows of diaphragms in one of said walls, a terminal rod supported in the chest and extending longitudinally centrally be tween said spaced rows of diaphragms, contact members hinged to said terminal rod and extending to either side thereof and resting on the rows of diaphragms to be selectively displaced thereby toward the other wall of said chest, and spaced rows of contact terminals extending through and sealed in the latter wall of the chest in alignment with the free ends of said hinged contact members to be engaged thereby, said spaced rows of contacts having means exterior to the chest for detachably receiving conductor wires.

GARNET E. HARRIS. WILLIAM STUBBINS. 

